Structural Dynamic Performance Evaluation of Industrial Robots Based on Vibration Tests

摘要

Industrial robots have been widely used in industrial production because of their reliability and efficiency. However, due to the structural flexibility of joints and links, industrial robots have poor rigidity and are prone to vibration compared with machine tools, which has become a bottleneck for their applications in tasks with dynamic loading such as machining. This issue has brought a need for an efficient method for performance evaluation of structural dynamics of industrial robots. For this purpose, this paper proposes a local performance index to quantify the structural dynamic performance of industrial robots based on vibration excitation test data. The characteristics of robot dynamic behavior is represented by the Frequency Response Functions (FRF), which can be obtained through impact excitation tests. Then, a performance index is derived from the FRF, which provides a conservative means to evaluating the worst situation of end-effector response due to harmonic excitation with the amplitude of a unit force. The proposed dynamic performance index can be used for the optimization of robot configuration, workpiece position and machining process parameters to reduce vibrations in robotic machining.